Facing an avalanche of customer complaints about poor battery life in iPhones that are running the 3.1 firmware release, Apple Support has sent a selected group of users a profile enabling a power-logging mode, and has disseminated an 11-item questionnaire, including questions about email use as well as the frequency with which WiFi and Bluetooth are enabled.

The Battery Life Logging mode apparently writes to the user area of the phone's flash, as the test users are instructed not to sync for a few days while gathering data. They are also asked to disable the mode once the testing is complete, presumably to avoid flash overrun due to the growth of the log files.

The utility is enabled by an unsigned profile that was sent to a number of users who had reported the issue on Apple's support forum, and is accompanied bu a questionnaire that asks questions like “When you notice a power drop, does it seem to be a legitimate power drop, or rather an issue with the battery icon indicator?”

An iPhone repair technician interviewed by Computeworld noted that "the processor in the iPhone 3GS can use 50% more power in some situations than its predecessor." Aaron Vronko of Rapid Repair theorized "that Apple missed some key interactions between the iPhone's software and the processor in the last update that causes it to over-utilize the CPU, especially since [the complaints] came after the software update."

One would hope that a fix, once found, will be incorporated into the release scheduled for September 25 that will enable MMS messaging on all iPhones. Complaints about short battery life began with release 3.0, and reached a crescendo with the current release.